Multiple rectifier cooling system



Dec. 24, 1946. c. A. KOTTERMAN 2,412,939

MMMMM PLfi RECTIFIER COOLING SYSTEM Filed July 3, 1942 4 Sheets-Sheet 1INVENTOR. CHESTER AJrUTTEfiM/W FIGJ.

Dec. 24, 1946. c. A. KOTTERMAN 2,412,939

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MULTIPLE RECTIFIER COOLING SYSTEM Filed July 3, 1942 4 Sheets-Sheet 3FIG.3.

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Dec. 24, 1946. c A. KOTTERMAN 2,412,989

MULTIPLE RECTIFIER COOLING SYSTEM Filed July 5, 1942 4 Sheets-Sheet 4 a0 59cm INVENTORf CHESTER A. HGTTERMAN ATT EY.

Patented Dec. 24, 1946 MULTIPLE aao'rmna coomno SYSTEM Chester A.Kotterman, Livingston, N. J., assignor to Federal Telephone and RadioCorporation, a corporation of Delaware Application July 3, 1942, SerialNo. 449,582

This invention relates to rectifiers of the metal plate type andparticularly to a unitary arrangement for cooling 3, number of suchrectifiers.

The object of the present invention is to provide a compact arrangementfor passing a fiow of cooling fluid such as air over the surface of therectifiers.

This object is carried out in accordance with this invention byarranging the rectifier units edgewise at narrow outlets from acompartment in which the cooling fluid pressure is built up so as to beforced through the outlets against the edges and over the surfaces ofthe rectifier units. The invention will be better understood from thefollowing detailed description and the accompanying drawings of which:

Fig. 1 is a plan view partially in section of a rectifier coolingarrangement according to this invention;

Fig. 2 is an elevation view, partially shown in section taken at line2-2 of Fig. 1;

Fig. 3 is a side view of a rectifier unit containing a number ofrectifier elements;

Fig. 4 is a section taken at line 4-4 of Fig. 3;

Fig. 5 shows a detail of the arrangement of the rectifier elements inFigs. 3 and 4;

Fig. 6 shows a plan view in section of a difierent form of coolingarrangement according to this invention; and

Fig. '7 shows a longitudinal section taken at line 1-1 of Fig. 6.

Referring to Figs. 1 and 2, the cooling arrangement is centered on acubicle l in the form of a. prism formed by four parallel corner strips2 which may be angle pieces. The top and bottom of the prism are closedby solid walls 3 and 4 respectively and the ends are closed by end walls5 and 6 respectively. The two remaining walls, these being the sidewalls, are formed by a plurality of channel members 1 having a generallyU-shaped cross section. The adjacent walls of adjacent channel memberspreferably converge toward each other as shown. The members I extendvertically between the respective upper and lower members 2 to whichthey are attached in any suitable manner as by bolts. The membets 1 arespaced apart at intervals which are preferably uniform so as to form aplurality of vertical slits 8 in the side walls.

The end walls 5 and 6 contain openings 9 and i0 respectively, preferablycircular, in which are placed respective motor driven fans ll and i2which blow air into the cubicle to build up a pressure in .it andthereby cause air to be forced out through the slots 8.

11 Claims.

The individual rectifier units 13 to be cooled are placed edgewise atthe respective slots 8 as shown. This invention is not concerned withthe particular construction of the rectifier units, as any form whichcan be shaped to fit the construction may be used. Examples of suchrectifying units are described in my copending application Ser. No.436,711, filed March 28, 1942. One of the units in the form shown inFigs. 1 and 2 is illustrated in greater detail in Figs. 3, 4 and 5. Inthis form, each unit comprises a supporting plate l4, which may forexample be of steel or aluminum, and carries on its two sides rectifierelements l5 shown in the form of discs l6 such as steel, coated in awell-known manner with a semi-conducting layer I! such as selenium. Whenthe rectifier is of the selenium type, it will have over the seleniumlayer a metallic counter-electrode layer 18 which is placed into contactwith the supporting plate H. Insulating rings l9 and 20 shouldpreferably be placed around the internal and external peripheries of thecounter-electrode to keep the selenium and the base plate l6 out ofcontact with plate H. These rings l9 may be of any suitable insulatingmaterial such as paper, or they may be composed of an application ofvarnish, which may be made to cover not only the exposed parts of theselenium layer but also the adjacent portions of the counterelectrodelayer. The rectifier elements 15 are fastened to the plate M by bolts 2|passing through the elements and the plate and tightened by nuts 22. Asuitable bus bar 23 is fastened under the nuts 22 to make contact.Washers 24 should be of conducting material so that the base plates ISon both sides of plate M are connected to each other, but insulatingbushings 25 around the bolts keep the bolts out of contact withsupporting plate 14. The bus bars constitute one terminal of theparallel connected rectifying elements l5 and plate I4 constitutes theother terminal. It will be understood that the rectifier elements 15need not be arranged exactly as shown; for example they might be placedon only one side of plate 14.

The rectifying units 13 are connected in position with relation tocubicle l by means of brackets 54 and 55 which fasten to the respectivecorner strips 2 of the cubicle. The corner strips should preferably beof an insulating material such as Bakelite; or if the strips 2 are ofconducting material the plates I4 should ordinarily be insulated fromthese strips so that all of plates M will not be connected together.This will allow for difierent connection arrangements between difierentrectifier units. In the case of a single arm type of rectifierconnection wherein all the rectifier units are in parallel, it would notmatter whether plates I4 are electrically connected together, butusually in a rectifier all of the units will not be connected inparallel.

The arrangement shown permits a considerable space within the cubiclewithin which an operating transformer 26 of the rectifier may be placedas shown if desired; and this may be mounted upon suitable supports 2?.

In the operation of the cooling system as thus described the fans II andi2 will blow air into the cubicle and will pass out through the slits 8between strips 1, the adjacent converging walls of adjacent strips 1serving to direct the air from each slit against the edge of thecorresponding plate l4 and over the surfaces of plate it and rectifyingelements l5 thereof. The direction of air flow is indicated by thearrows in Fig. 1. Preferably, the combined area of openings 9 and ishould be equal to or greater than the combined area of the slits 8.

An efiicient arrangement is one in which the cubic l bearing therectifier units I3 is placed within an enclosure 28 which completelycontains all of the circulating air or fluid. In such construction, thecirculating air or fiuid should be cooled by heat exchangers 29 and atbefore the hot air or fluid from the rectifiers reaches the fans again.The heat xchangers shown comprise fiuid cooled pipes 3| arranged in asupporting housing 32 attached over the walls and 6 of the cubicle. Thehousing 32 is composed of struts 33 projecting from the walls 5 and 6 towhich are attached partitioning walls 34 and 35 closing the top andbottom of the housing. The wall 85 serves to close the front of thehousing. As there are no side walls extending between the top and bottomwalls 34 and 35, the only path for entry of air into the housing isthrough the spaces between cooling pipes 3!. By this arrangement the airblown out of the cubicle i over the rectifier elements returns to thefans through the I spaces 31 between the ends of the rectifier units andthe enclosure 28 and through the heat exchangers. Cooled fiuidcirculated through pipes 3! provides the cooling. For convenience thewalls of enclosure I may be made removable as indicated at 38 and 39 toallow access to the interior.

Figs. 6 and 7 illustrate a somewhat different modification wherein theenclosure in which the air pressure is built up is in the form of acylinder or drum around which the rectifier units are fastened. The drumis formed by a pair of circular end pieces 40 and M, the latter having acircular cutout 42 to permit access of cooling fan 43. To the circularend members 40 and ti there are fastened circular hoops 44 and 65respectively which may be channel shaped in cross section as shown.Extending vertically between the hoops are the spaced strips 1 of U-shaped cross section as in Fig. 1 and having the spaces or slots 8between them. The rectifier units I3 are fastened by their brackets 25to the hoops 44 and 45 as shown so that the plates I4 are located in theslots 8 between adjacent strips 7 as in the case of Fig. 1. This drumarrangement is preferably operated so the plates l4 lie in a verticalplane as shown, and for this purpose, a suitable stand or legs 46 may befastened to a base member 41 to which the fan motor 48 may also beattached.

Although in this embodiment only one fan is shown, it will be understoodthat a fan may be placed at both ends as in Fig. 1 instead of only atone end. Furthermore, in the construction shown in Figs. 6 and 7 thereis shown no heat exchanger nor outer enclosure as in Fig. 1 as in thiscase the air of the atmsophere is cooling the rectifiers. A suitableheat exchanger and enclosure could of course be provided in a mannersimilar to Figs. 1 and 2 if desired.

What I claim is:

1. In a multiple rectifier, a casing, a plurality of plates eachcarrying a plurality of rectifier elements each mounted in direct heattransfer relation on at least one of its faces, a mounting for saidplates holding them side by side within said casing, and means forcirculating cooling fluid in said casing between said plates and causingit to strike the edges of said plates and fiow over the surfacesthereof, and the rectifier elements thereon.

2. In a multiple rectifier, a casing, a plurality of plates eachcarrying a plurality of rectifier elements on its two faces, a mountingfor said plates holding them within said casing substantially parallelwith one another, and means for circulating cooling fluid in said casingbetween said plates and causing it to strike the edges of said platesand flow over the surfaces thereof, and the rectifier elements thereon.

3. In a multiple rectifier, a casing, a plurality of plates eachcarrying a plurality of rectifier elements each mounted in direct heattransfer relation on at least one of its two faces, a mounting for saidplates holding them within said casing spaced from one another andsubstantially at right-angles to the side walls, and means forcirculating cooling fluid in said casing between said plates past saidrectifier elements.

4.. In a multiple rectifier, a casing having end and side walls, aplurality of plates each carrying a pluralityof rectifier elements onits two faces, a mounting for said plates holding them within saidcasing uniformly spaced parallel with one another and substantially atright-angles to the side walls but spaced therefrom, a. heat exchangerat each end wall, and a blower centrally located in the casing near eachend wall and circulating cooling fluid over the associated heatexchanger, between said plates past the rectifier elements thereon andback through the space between the plates and the casing to the heatexchanger.

5. In a multiple rectifier, a cylindrical casing, a plurality of plateseach carrying a plurality of rectifier elements on at least one of itsfaces, a mounting for said plates holding them within said casing spacedwith respect to the side walls but separated therefrom, a heat exchangerat each end of the casing, and a blower centrally located in the casingnear each end and circulating cooling fluid over the associatedexchanger between said plates past the rectifier elements thereon andback through the space between the plates and the casing to the heatexchanger. 7

6. In a multiple rectifier, a cylindrical casing, a plurality of plateseach carrying a plurality of rectifier elements on its two faces, amounting for said plates holding them within said casing uniformlyspaced radially with respect to the side walls but separated therefrom,a heat exchanger at each end of, the casing, and a blower centrallylocated in the casing near each end and circulating cooling fluid overthe associated heat exchanger, between said plates past the rectifierelements thereon and back through the space between the plates and thecasing to the heat exchanger.

7. A rectifier cooling system comprising a chamber, an opening in saidchamber, a fan at said opening to blow air into said chamber, slots insaid chamber with means at the slots for directing the fiow of airtherethrough, said airdirecting means at the slots being formed byspaced strips having adjacent walls which converge toward each other inthe direction of air flow, and a rectifier unit placed edgewise at eachslot so as to receive on its edge from said directing means air blownthrough the slot from inside said chamber, whereby the air divides atthe edge and blows over both surfaces of said rectifier unit.

8. A rectifier cooling system, comprising means forming a chamber havinga relatively large opening and a plurality of slots therein, wall meanson opposite edges of each slot extending outwardly from said chamber andconverging toward one another, a rectifier placed edgewise between theconverging walls at each slot in a plane parallel to the longitudinaledge of the slot,

and means blowing a cooling fluid into said chamber through saidopening, whereby said cooling fluid passes outwardly of said chamberthrough said slots and between said converging walls, and over bothsides of the rectifier units.

9. The combination according to claim 8, in which said wall meanscomprise integral extensions of said chamber-forming means.

10. A rectifier cooling system, comprising means forming a chamberhaving a relatively large opening and a plurality of slots therein, wallmeans on opposite edges of each slot, extending outwardly from saidchamber, a rectifier placed edgewise between the walls at each slot in aplane parallel to the longitudinal edge of th slot, and means blowing acooling fluid into said chamber through said opening, whereby coolingfiuid passes outwardly of said chamber through said slots and betweensaid walls, and over both sides of the rectifier units.

11. The combination according to claim 10, in which said wall meanscomprise integral extensions of said chamber-forming means.

CHESTER A. KOT'I'ERMAN.

